In recent years, we've watched with wonder as boring old yellow halogen car headlights have been replaced with futuristic, Tron-like LEDs. Now, that transition is about to take place on the city scale, as New York City prepares to replace its street lamps—all 250,000 of them—with LEDs.

Mayor Bloomberg announced the massive project on Thursday, pointing out straight away that the shift to LEDs would save the city $6 million in energy costs and $8 million in maintenance—that's $14 million total, math whizzes—every year. That's not even counting the long-term environmental effects of the energy conservation. With the announcement, Transportation Commissioner Janette Sadik-Khan was ready with the puns: "Using LEDs for street lighting is more than just a bright idea, it’s a necessity for sustainable cities to operate more efficiently while also delivering clearer, better quality light for New Yorkers." While testing has been underway for years, the transition should be complete by 2017.

Indeed, New York is not the only city to take this more sustainable route. Earlier this year, Los Angeles completed the first phase of the world’s largest LED street light replacement project to date, though New York's 250,000 will eclipse that figure. Smaller cities like St. Paul and even Las Vegas have also made the transition and saved taxpayers millions of dollars.